jack harrison

hi guys, just got my new edelbrock hi performer intake. looks like a really nice bit of kit. couple of things though, first, will it really make any differance to my 350 tpi? the openings arent that much bigger than on the stock intake. also, at the back of the edelbrock heads that ive got there are a couple of water ways, but on the stock intake there was no where for the water to go. how ever this new intake has a water jacket the will join to the head openings up. is this normal? cheers guys.

Russ-So Cal

Are you looking at water passages or egr passages?

jack harrison

DEFFINATLY water jackets. theres water still in the heads.

jack harrison

anyone??

RPOL98

i'm assuming you're talking about the Edelbrock TPI manifold base.

on the TPI corvettes, the rear water passage is indeed put to use and a small hose & tubing is routed to the heater plumbing. on TPI IROCs, it isn't used.

IIRC, on the drivers' side, where the TPI runner bolts go into the manifold, at the rear, one of those bolts goes into this water crossover. be sure to use thread sealant on that bolt.

jack harrison

it is indded a tpi base. thanks for the advice about sealant on the bolts. when this crappy weather clears ill put it all back together!

RPOL98

if you haven't put it on yet, you might consider porting it a little, to clean up the runner transitions where the Edelbrock factory machining ends. it's pretty easy to do, easy to reach and very visible.

on my TPI IROC, I had to grind a little at the back of the water thermostat housing to clear the factory t-stat housing, and also a little at the EGR valve (I used a block-off plate). very minor.

hopefully, you're using aftermarket runners (e.g. SLP, etc) to get the full benefit. if so, consider larger TPI runner gaskets, Mr. Gasket #146.

and of course, while you're at it, you're porting at least the front opening of your plenum to get rid of that bottom ridge.

sounds like a lot of "while you're at it" things...

jack harrison

i checked the transition points you mentioned and they seem fine. i really want to see what differance the stock intake makes first before i start porting stuff! and i am inded using slp runners, i think they're great. and also i have grinded out the plenum to the max! thanks for the great info dude.